Construction of Flocculent Yeast Cells (Saccharomyces cerevisiae) by Mating or Protoplast Fusion Using a Yeast Cell Containing the Flocculation Gene FL05

In the yeast Saccharomyces cerevisiae, the gene FL01 and the gene FL05 are dominant flocculation genes. In diploid cells heterozygous for MAT, however, expression of the FL01 gene was greatly diminished as far as we examined, as seen in the FL08 gene. On the other hand, expression of the FL05 gene was not affected by the mating-type locus. Several brewer’s and wine flocculent yeast cells showed the flocculence phenotype defined as the FL05 type. These results suggested the usefulness of the FL05 gene in improvement of the flocculation properties of industrial strains.